1. Field of the Invention
The present invention relates generally to the field of structural separation mechanisms. More particularly, the present invention relates to the field of hold-down and release mechanism for flight termination-systems.
2. Description of the Prior Art
Structural separation mechanisms are widely used in aerospace, manufacturing and construction industries. The main purpose of utilizing a structural separation mechanism is to release an externally attached structural object in a quick and reliable manner without damaging the external structural object.
The following five (5) prior art patents are found to be pertinent to the field of the present invention:
1. U.S. Pat. No. 3,115,836 issued to Brashears on Dec. 31, 1963 for xe2x80x9cClamping Ring Release Mechanismxe2x80x9d (hereafter the xe2x80x9cBrashears Patentxe2x80x9d);
2. U.S. Pat. No. 3,229,636 issued to Mayo et al. on Jan. 18, 1966 for xe2x80x9cMissile Stage Separation Indicator And Stage Initiatorsxe2x80x9d (hereafter the xe2x80x9cMayo Patentxe2x80x9d);
3. U.S. Pat. No. 3,513,512 issued to Phillips on May 26, 1970 for xe2x80x9cFastening Assembly With Quick Releasexe2x80x9d (hereafter the xe2x80x9cPhillips Patentxe2x80x9d);
4. U.S. Pat. No. 3,863,570 issued to Bixby on Feb. 4, 1975 for xe2x80x9cHydraulic Pressure Actuated Missile Stage Separationxe2x80x9d (hereafter the xe2x80x9cBixby Patentxe2x80x9d); and
5. U.S. Pat. No. 4,007,688 issued to Franz on Feb. 15, 1977 for xe2x80x9cTimed Missile Flight Termination Systemxe2x80x9d (hereafter the xe2x80x9cFranz Patentxe2x80x9d).
The Brashears Patent discloses a clamping ring release mechanism having a sensing cylinder in which a piston disposed within the cylinder responds to a drop in pressure. The pressure drop then actuates a microswitch. The sensing cylinder is mounted on the booster of a missile-booster combination and actuated by pressure bled from the booster chamber. The piston of the sensing cylinder, in responding to a drop in booster pressure at boost phase termination, actuates a microswitch which closes a circuit from a thermal battery to an explosive containing cylinder that is also mounted on the booster. The explosive containing cylinder upon detonation, releases a scissors mechanism holding together a clamping ring that couples the missile to the booster.
The Mayo Patent discloses a missile stage separation indicator and stage initiator. It comprises a piston, a spring, and a lever assembly for generating an electric pulse. The mechanism is designed to separate two stages of a missile.
The Phillips Patent discloses a fastening assembly with a quick release. The Phillips Patent is cited as being of general interest with respect to a piston, a cylinder or a spring separation assembly for a missile and the like.
The Bixby Patent discloses a hydraulic pressure actuated missile stage separation. The separation mechanism includes a piston, a cylinder or a spring separation assembly for a missile and the like.
The Franz Patent discloses a timed missile flight termination system. It comprises a pressure activated, timed missile flight termination system. The system is activated by pressure created within the combustion chamber of the missile to activate a time delay fuse. The fuse is therefore activated instantaneously with ignition of the missile. The delay fuse provides a predetermined period before the designation of a linear-shaped charge to terminate the flight of the missile.
While various approaches were developed in the prior art in the field of structural separation mechanisms, most conventional flight termination systems use pyrotechnic devices in their structural separation mechanisms.
Therefore, it is still highly desirable to design and construct a new resettable and redundant hold-down and release mechanism for a flight termination system. It is also highly desirable to design and construct a resettable and redundant hold-down and release mechanism which can be initiated by refurbishable non-explosive actuators (NEAs).
The present invention is a novel and unique resettable and redundant non-explosive actuator (NEA) initiated hold-down and release mechanism for a flight termination system.
It is an object of the present invention to provide a hold-down and release mechanism for flight termination systems.
It is also an object of the present invention to provide a resettable hold-down and release mechanism for flight termination systems.
It is another object of the present invention to provide a redundant hold-down and release mechanism for flight termination systems.
It is a further object of the present invention to provide a non-explosive actuator (NEA) initiated hold-down and release mechanism for flight termination systems.
Described briefly in general terms, the present invention is a hold-down and release apparatus for a flight termination system for holding-down and releasing a structural object; the flight termination system having a generally cylindrical shaped end portion with an end opening, and the structural object having a generally cylindrical shaped end portion with a circular engagement member. The hold-down and release apparatus includes a circular engagement sleeve mounted inside the end opening of the generally cylindrical shaped end portion of the flight termination system for receiving the circular engagement member of the generally cylindrical shaped end portion of the structural object. The hold-down and release apparatus also includes a circumferential external circular groove provided on the circular engagement member of the structural object.
The circular engagement sleeve has a multiplicity of internal clamping segments symmetrically located in a circular cavity between the circular sleeve and a sidewall of the generally cylindrical shaped end portion of the flight termination system; each internal clamping segment extending through a slot on the circular engagement sleeve respectively to engage into the circular groove of the circular engagement member of the structural object to hold-down the structural object when the circular engagement member of the structural object is inserted into the circular engagement sleeve of the flight termination system. Each one of the clamping segments is movable along a radial direction and biased by internal compression springs which push each respective clamping segment to move radially outwardly along the radial direction if unrestrained.
The hold-down and release apparatus further includes a generally circular release band wound around the multiplicity of movable clamping segments to counter the compression springs and restrain the outward movement of said internal clamping segments such that the clamping segments remain extending inwardly through the slot on the circular sleeve and engaging into the circular groove of the circular engagement member of the structural object for holding-down the structural object.
The circular release band has two ends each being held in place by a non-explosive actuator (NEA), where either one or both NEAs may initiate the release of a respective one or both of the two ends of the circular release band which loosens the circular release band around the clamping segments, which in turn allows the clamping segments to move radially outwardly under the bias force of the compression spring and disengage from the circular groove of the circular engagement member of the structural object, to release the structural object from the flight termination system.
The present invention has many advantages. The major advantage of the present invention is that it provides a structural separation mechanism that is resettable and redundant. Another major advantage of the present invention is that it provides a structural separation mechanism that can be initiated by refurbishable NEAs. These features of the present invention provide superior safety, reliability and cost-effectiveness.
Further novel features and other objects of the present invention will become apparent from the following detailed description, discussion and the appended claims, taken in conjunction with the drawings.